SharkWater Trading  •  Nuclear Desk • Analyst Calls • Small Modular Reactors

X-Energy Is Down 17 Percent Since Piper Sandler Said Sell. Oklo's Buy Rating Isn't Holding Up Much Better.

September 11, 2026

Bottom Line Up Front

Piper Sandler initiated Oklo (NYSE: OKLO) at Buy with a $55 price target and X-Energy (Nasdaq: XE) at Sell with a $9 price target, in a note dated September 9. Since that close, XE has fallen from $19.15 to $15.84, down roughly 17 percent, while OKLO has fallen from $43.31 to $39.88, down roughly 8 percent, over the same three sessions.

Both stocks are still unwinding a September 8 nuclear-sector spike that multiple outlets called catalyst-free before Piper Sandler ever weighed in. The Sell call on X-Energy is behaving the way a Sell call should. The Buy call on Oklo is not yet behaving the way a Buy call should, and that gap is the actual story here.

The Call

Piper Sandler analyst Dimple Gosai split the small modular reactor sector down the middle. Oklo got a Buy rating and a $55 target, a little under 38 percent above Thursday's close. X-Energy got a Sell and a $9 target, roughly 43 percent below Thursday's close. The stated reasoning, per coverage of the note, comes down to financing structure: Oklo runs a build-own-operate model the analyst called "bankable by design," while X-Energy licenses its reactor technology to customers under an asset-light approach that shifts project execution risk onto those customers instead of keeping it on X-Energy's own balance sheet.

That is a real, testable thesis about who eats the risk when a first-of-a-kind reactor project runs long or over budget. It is not a comment on which company has the better technology, and this desk isn't in a position to referee that engineering question. What we can track is whether the market is pricing the difference the way the ratings imply it should.

What the Tape Says

So far, it is pricing one half of it. X-Energy has fallen in a straight line since the call, exactly what a Sell rating with 43 percent downside implied should happen if the market agreed. Oklo has also fallen every session since, including a 6.32 percent drop Thursday that accelerated rather than stabilized. A stock carrying a fresh Buy rating with 38 percent of implied upside is not supposed to be having its worst single day of the week two days after the call.

Ticker	Sept 8 Close	Sept 9 Close	Sept 10 Close	Cumulative
OKLO	$43.31	$42.57 (-1.71%)	$39.88 (-6.32%)	-7.9%
XE	$19.15	$17.26 (-9.87%)	$15.84 (-8.26%)	-17.3%

Source: stockanalysis.com, an aggregator, not a primary source. A separate aggregator (MarketBeat) puts XE's September 9 close at $18.03 (-5.8 percent) rather than $17.26 (-9.87 percent); the two did not reconcile this week, so treat the exact size of X-Energy's single-day drop as approximate. The direction and the relative underperformance versus Oklo hold under either version. Oklo's Thursday volume ran about 1.17 times its 20-day average, not a capitulation print.

A split rating is a bet that two boats caught in the same swell will handle it differently once the wave passes. Right now both are still pitching. Only one of them is supposed to be.

The One Filing That Matters

Away from the rating, the only fresh SEC paper on either name this week is a Schedule 13G filed September 4 by Jane Street Group, LLC, disclosing a new passive stake of 5.2 percent in X-Energy. It states no activist intent and no plan to influence control. That is a market-making and index-flow signal, not a fundamental one, and it predates the Piper Sandler call by five days. Nothing in EDGAR corroborates or contradicts the thesis itself for either stock.

The Bull Case

• Piper Sandler's own math still points up. A $55 target against Thursday's $39.88 close is real, stated upside from a firm that just put a differentiated thesis in writing, not a vague "AI nuclear theme" call.
• Oklo's decline hasn't come on panic volume. Thursday's drop ran close to average turnover. That is consistent with sellers unwinding the same September 8 spike everyone else is unwinding, not with new information breaking against the stock specifically.
• The policy backdrop keeps getting louder, even if it isn't confirmed. Reporting on a US-Korea nuclear cooperation package, now sourced to the Wall Street Journal and a Korean outlet and not just one anonymous-sourced piece, describes a deal in the $100 billion range covering up to eight reactors. It names no companies on this watchlist and remains tentative, but it is evidence the sector narrative has more than one leg to stand on.

The Bear Case

• A Buy-rated stock accelerating its losses two days after the rating is a bad look, not a rounding error. If Piper Sandler's differentiated thesis were actually driving the tape, Oklo should be outperforming, not just losing less.
• The whole rally this is unwinding was never explained in the first place. September 8's spike across Oklo, X-Energy, and NuScale was described by multiple outlets as catalyst-free, tied to short-covering and sector rotation rather than any company-specific news. A thesis about financing structure doesn't need to be wrong for a name to keep falling simply because the move it's riding on top of was never real.
• X-Energy's Sell rating implies another 43 percent of downside from here. A stock already down 17 percent in three sessions that still carries that much stated downside, from the same analyst who just called it, is not a name to catch on the way down without a reason the price has actually stopped falling.

The SharkWater Take

I believe the Sell call on X-Energy before I believe the Buy call on Oklo, and the price action is telling me exactly that. X-Energy is falling the way a stock falls when a real thesis lands on top of a fake rally. Oklo is falling the way a stock falls when the fake rally hasn't finished unwinding yet, Buy rating or not. Until Oklo actually decouples, holding a green day or outperforming X-Energy on a bad tape rather than just losing less of it, I'm not treating Piper Sandler's split as confirmed by the market, only asserted by the analyst. I'd rather watch X-Energy keep validating the bear side of this call from the sidelines than buy Oklo on a thesis the stock itself hasn't started agreeing with.

Tight lines. — SharkWater

Educational and informational purposes only. Not personalized investment advice. Price targets referenced above are Piper Sandler's, as reported, not SharkWater's own forecasts. All figures sourced as noted; several are aggregator-sourced (stockanalysis.com, MarketBeat) rather than exchange-primary and are labeled accordingly, and two aggregators disagree on X-Energy's September 9 closing figure. Options involve substantial risk of loss. The author may hold positions in securities discussed. Do your own work.